100 ATOMIC WEIGHT DETERMINATIONS, 



C. Marignac : 39.115 (O = 16) ; 244.47 (0 = 100). 



Having determined the atomic weight of chlorine from 

 syntheses of argentic chloride, and found it 443.2, the 

 molecular weight of KCl in the last determination, gives 

 K = 244.47, for vacuum. Berzelius, by rejecting some 

 analyses and the correction for vacuum, deduces the value 

 244.429. {Berzelius' Jahresbericht, 26, 1845, 31 ; Bibl. Uiiiv. 

 de Geyieve, ^6, 1842, 350.) 



J. Pelouze : 39. lU (0 = 16); 244.65 (O = 100). 



A known weight of KCl was brought into contact with a 

 known amount of silver dissolved in nitric acid, the chlo- 

 ride being slightly in excess. This excess was titrated with 

 a decimal solution of silver. The number is the mean of 

 three experiments. Ag = 1349.01 ; CI = 443.2. The chlo- 

 ride was prepared by heating the chlorate and recrystalliz- 

 ing the residue. {Paris Comptes Rend., W, 1845, 1047.) 



According to Pelouze, Levol found the molecular weight 

 of KCl 466.245, which combined with Marignac's value of 

 CI would give K = 244.645 or 39.11,3. {Ibid.) 



E. J. Maumene : 38.96 (0 = 16) ; 243.502 (O = 

 100.) 



The mean of three experiments on the decomposition of 

 KCl with an excess of argentic nitrate showed that 100 

 KCl = 192.75 AgCl. If Ag = 1350.32 and CI =443.67, 

 according to Maumene's determinations, the number fol- 

 lows. The KCl was prepared from the chlorate by heat. 

 To coriiirm his values for K and CI, he made seven experi- 

 ments on the decomposition of the chlorate by heat, and 

 found that 100 chlorate gave 60.791 chloride. An unac- 

 counted for increase in the weight of the flask occurred in 

 these experiments. {Annal. de Chim. et de Phys., (3,) 18, 

 1846, 41.) 



J. S. Stas : 39.137 (O = 16). 



According to the mean of seven determinations, 100 

 parts of KCl dissolved in nitric acid, and evaporated to 

 drj'ness give 135.6423 parts of nitrate ; extreme difiference, 

 0.017. If CI = 35.457; N = 14.044; the value follows. 

 This value is confirmed by previous experiments which 

 gave 39.130. Potassic chloride, by whatever means it is 

 prepared, still retains silica. Stas, therefore, determined 



